Forensic Chemist Receives DOJ Support for Gunshot Residue Detection Tool

Gunshot residue is important for helping forensic investigators reconstruct crime scenes where a firearm was used and link suspects to the event.

However, current detection methods are costly, time-consuming and often destroy the sample for future testing.

Igor Lednev, a chemist at the University at Albany, is working to develop a new laser-based technology that relies on a combination of Raman spectroscopy and machine learning to quickly analyze crime scene evidence, including gunshot residue.

His research is now one step closer to helping law enforcement through a $556,572 grant awarded by the U.S. Department of Justice (DOJ) in January.

"Gunshot residue is a complex mixture of particles, including partially burned propellant, primer and cartridge case materials, that is left behind on hands, clothing and surfaces following a firearm discharge. It provides crucial evidence in shooting-related cases," said Lednev, a Distinguished Professor in UAlbany's Department of Chemistry. "Currently, there is a great need for a fast, accurate and non-destructive method to detect these particles at crime scenes, which we believe can be achieved through our novel technology."

Laser Forensics

Raman spectroscopy is a non-destructive chemical analysis that works by shining monochromatic light on a sample and measuring the scattered radiation. No two samples produce the same scattered spectrum, offering a unique measurement (similar to a fingerprint). The results are nearly instantaneous, and preserve the sample for future testing.

Lednev's technology combines this analysis with advanced statistics to identify the chemical composition of trace evidence left at a crime scene—such as body fluid or particles released from gunfire.

The new DOJ funding will be used by the Lednev lab to test their technique on gunshot residue that is trapped inside common fabrics, which are often missed in current investigations. They will then expand to testing small traces of evidence from other surfaces and objects, collected using sticky tape or another type of adhesive.

"We have developed a two-step method for the detection and identification of gunshot residue, first using a highly sensitive fluorescence hyperspectral imaging of a sample area to detect potential particles, followed by confirmatory identification of particles using Raman spectroscopy," Lednev said. "Once identification is achieved, we can further our analysis including determining other important information such as the type of ammunition and/or ammunition manufacturer."

Following the lab research, his team, which includes several UAlbany graduate students, plans to explore the development of a portable instrument that can be used to detect gunshot residue directly at the crime scene.

"Considering that handheld Raman spectroscopic instruments are already commercially available, we envision our technology will become portable in the future and put into the hands of investigators at crime scenes," Lednev said.

From the Lab to Courtroom

The NIJ grant will support Lednev's work for the next five years with collaboration from the New York State Police Forensic Investigation Center in Albany and the Onondaga County Center for Forensic Sciences in Syracuse.

The Lednev lab has advanced the use of Raman spectroscopy for forensic purposes for more than a decade. His team's research has been continuously funded by the NIJ, published more than 60 articles in peer-reviewed journals on the topic, and received three U.S. patents.

SupreMEtric LLC, a startup founded by Lednev that is focused on identifying body fluid traces at crime scenes, has received more than $1 million in support from the National Science Foundation to help bring the technology to market.

Lednev believes there's potential to combine his technologies into a single instrument.

"We have made significant progress in the development of another tool that can detect and identify body fluid traces for forensic purposes," Lednev said. "SupreMEtric LLC is commercializing this patented technology now. We'd like to see our body fluid and gun residue analysis combined into a single instrument, making it a really powerful forensic tool."

Provided by University at Albany